From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7D1FEC64E7B for ; Mon, 30 Nov 2020 13:06:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2707F221EB for ; Mon, 30 Nov 2020 13:06:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726214AbgK3NGn (ORCPT ); Mon, 30 Nov 2020 08:06:43 -0500 Received: from szxga05-in.huawei.com ([45.249.212.191]:8534 "EHLO szxga05-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726178AbgK3NGn (ORCPT ); Mon, 30 Nov 2020 08:06:43 -0500 Received: from DGGEMS402-HUB.china.huawei.com (unknown [172.30.72.59]) by szxga05-in.huawei.com (SkyGuard) with ESMTP id 4Cl57f2r5JzhkqD; Mon, 30 Nov 2020 21:05:34 +0800 (CST) Received: from [10.174.177.149] (10.174.177.149) by DGGEMS402-HUB.china.huawei.com (10.3.19.202) with Microsoft SMTP Server id 14.3.487.0; Mon, 30 Nov 2020 21:05:55 +0800 Subject: Re: [PATCH] hwrng: exynos - fix reference leak in exynos_trng_probe To: Lukasz Stelmach CC: Krzysztof Kozlowski , , , , References: <20201127094446.121277-1-miaoqinglang@huawei.com> From: Qinglang Miao Message-ID: <3ed654dd-db10-0975-d125-a3949c9bab90@huawei.com> Date: Mon, 30 Nov 2020 21:05:55 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.174.177.149] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org 在 2020/11/27 22:26, Lukasz Stelmach 写道: > It was <2020-11-27 pią 17:44>, when Qinglang Miao wrote: >> pm_runtime_get_sync will increment pm usage counter even it >> failed. Forgetting to putting operation will result in a >> reference leak here. >> >> A new function pm_runtime_resume_and_get is introduced in >> [0] to keep usage counter balanced. So We fix the reference >> leak by replacing it with new funtion. >> >> [0] dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter") >> >> Fixes: 6cd225cc5d8a ("hwrng: exynos - add Samsung Exynos True RNG driver") >> Reported-by: Hulk Robot >> Signed-off-by: Qinglang Miao >> --- >> drivers/char/hw_random/exynos-trng.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/char/hw_random/exynos-trng.c b/drivers/char/hw_random/exynos-trng.c >> index 8e1fe3f8d..666246bc8 100644 >> --- a/drivers/char/hw_random/exynos-trng.c >> +++ b/drivers/char/hw_random/exynos-trng.c >> @@ -132,7 +132,7 @@ static int exynos_trng_probe(struct platform_device *pdev) >> return PTR_ERR(trng->mem); >> >> pm_runtime_enable(&pdev->dev); >> - ret = pm_runtime_get_sync(&pdev->dev); >> + ret = pm_runtime_resume_and_get(&pdev->dev); >> if (ret < 0) { >> dev_err(&pdev->dev, "Could not get runtime PM.\n"); >> goto err_pm_get; > > Thanks. I suppose you may use the new function exynos_trng_resume(), > remove everything and leave only > > return pm_runtime_resume_and_get(dev); Hi, Lukasz I sent a v2 on this one. But I'm not really sure about what does 'remove everything' mean. for example, should I remove exynos_trng_resume in this patch? Thanks. >